Doepfer

Hi Nicholas

>   I don't understand the pot shown for soft sync connection, nor the 
> required values for lin FM pot.  If you did the mod, can you confirm
> that the typical A-100 component values will work here (b50k pot)?  
> Did you add the AC/DC switch or jumper?  And what is the soft sync 
> pot for, is it a misprint?  

I used not a pot for the softsync input but a 47k resistor to ground 
(equivalent to 50kpot fully turned clock wise). The pot is used to trim 
the softsync signal in the kind of a threshold; the sync signal is fed 
directly to the comparator, which triggers the unloading of C3; so if a 
saw is used as sync signal the level of the sigal determines when and 
how long c3 is resetted; if you use a narrow rectangle as sync signal, a 
trimming is not required.

For the lin FM pot I used the 50kPot for the log FM (i simply removed R7 
temporarily and connected the slider of the pot to R14. So I did not use 
the cap and the switch. It depends on what you want to do with it.



>   You also mentioned (I think it was you) the basic sine shaper 
> Doepfer uses and a variation shown online.....those links don't seem 
> to work anymore.  Do you know of another example online?  I tried to 
> find one but failed. 
As far as I know there are sine shapers with several diodes in 
antiparallel setup, but I do not know an online example for it.

>  I don't suppose you did the A-120 input mod?  
I want to do so.

> Sorry to beat a dead 
> horse here guys, but did YOU add the capacitor at C10 (I think, I'm 
> trying to recall) as well as the resistor at R15, or just the 
> resistor??  I've done it with the cap but haven't been home long 
> enough to test it.
As far as I remember the schematic the change does make sense only, if 
you have to add both (lower R and increase C). The RC pair is a passive 
filter in principle. If you change only the resistor (to increase the 
level of the signal), you change the cutoff frequency of this input 
stage. So, to keep the frequency of this "filter" you have to increase 
the capacitor.


Florian